Is the alternative to highway deaths to set the national speed limit at 10 MPH? Not everything needs an alternative, you just live with small risks.
If we have enough intelligence to know there are terrorist cells around, we should be able to find them before they get to the airport.
In reality I would expect the TSA to declare underwear must be worn on the outside of your pants, and you must pass through the WTMD backwards after answering who won the 1938 World Series.